Preventive or Remedy for Inflammatory Disease

ABSTRACT

The present inventors obtained, from a phage library of human antibodies, an anti-mouse NR 10 neutralizing antibody-expressing BM095 clone that shows a strong proliferation-suppressing activity in an IL-31-dependent Ba/F3 cell proliferation assay system. When this anti-mouse NR 10 neutralizing antibody was administered to NC/Nga mice, a model of atopic dermatitis which is a mouse model of chronic dermatitis that arises as a result of repeated applications of picryl chloride, a mouse model of rheumatoid arthritis, and a mouse model of osteoarthritis, a significant effect of symptom suppression was observed. This revealed that the anti-NR 10 neutralizing antibody is indeed effective as a therapeutic agent for inflammatory diseases. In addition, the present inventors successfully obtained an anti-human NR 10 neutralizing antibody, providing extremely useful therapeutic agents with practical clinical applications.

TECHNICAL FIELD

The present invention relates to novel agents for preventing or treating inflammatory diseases, which comprise NR 10 antagonists as active ingredients. The present invention also relates to methods for preventing or treating inflammatory diseases, which use NR 10 antagonists.

BACKGROUND ART

Many cytokines are known as humoral factors involved in the growth and differentiation of various types of cells, or in the activation of differentiated mature cell functions. Cytokine-stimulated cells produce different types of cytokines, thereby forming networks of multiple cytokines in the body. Biological homeostasis is maintained by a delicate balance of the mutual regulation between cytokines in these networks. Many inflammatory diseases are thought to result from a failure of such cytokine networks. Thus, monoclonal antibody-based anti-cytokine therapy is drawing much attention. For example, anti-TNF antibodies and anti-IL-6 receptor antibodies have been demonstrated to be highly effective clinically. On the other hand, there are many examples of failure where no therapeutic effects were produced when a single cytokine, such as IL-4, was blocked alone, due to the activation of compensatory pathways in actual pathological conditions.

The present inventors succeeded in isolating a novel cytokine receptor NR 10 that was highly homologous to gp130, a receptor for IL-6 signal transduction (Patent Document 1). NR 10 forms a heterodimer with oncostatin M receptor (OSMR) and functions as an IL-31 receptor (Non-patent Document 1). Zymogenetics, Inc. reported that transgenic mice overexpressing IL-31 spontaneously developed pruritic dermatitis (Patent Document 2).

However, it cannot be asserted that the forced expression of a cytokine in mice or a high blood level of a cytokine in pathological model mice is indeed the cause of a disease. There is no information on whether any therapeutic effects are produced when a signal is blocked by an antibody. For example, pruritic dermatitis develops in transgenic mice in which IL-18 is overexpressed in keratinocytes. Furthermore, the blood IL-18 concentration elevates with the progression of pathological conditions in NC/Nga model mice for spontaneous atopic dermatitis. Based on the above findings, the overexpression of IL-18 was predicted to be the cause of disease. In reality however, the administration of neutralizing antibodies produced no therapeutic effects (Non-patent Document 2).

As described above, inhibition of the function of a cytokine does not necessarily produce therapeutic effects in diseases in which the expression level of a cytokine is elevated. Prediction of diseases on which therapeutic effects are actually produced is difficult to make based on the expression level of a cytokine. It is thus important to find diseases in which inhibition of signal transduction of a target cytokine actually produces therapeutic effects.

Prior art documents of the present invention are described below.

Patent Document 1: WO 00/75314 Patent Document 2: WO 03/060090

Non-patent Document 1: IL-31 is associated with cutaneous lymphocyte antigen-positive skin homing T cells in patients with atopic dermatitis, J Allergy Clin Immunol. 2006 February; 117(2): 418-25 Non-patent Document 2: Administration of anti-interleukin 18 antibody fails to inhibit development of dermatitis in atopic dermatitis-model mice NC/Nga, British Journal of Dermatology 149: 39-45, 2003

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention

The present invention was achieved in view of the circumstances described above. An objective of the present invention is to provide cytokine receptor antagonist-based anti-cytokine therapies for inflammatory diseases. More specifically, the objective of the present invention is to discover inflammatory diseases in which a therapeutic effect may be obtained by anti-NR 10 neutralizing antibodies, and to provide novel methods for treating such diseases. Another objective of the present invention is to provide anti-human NR 10 neutralizing antibodies that are clinically applicable to humans.

Means for Solving the Problems

The present inventors conducted dedicated studies to solve the above-described objectives. The present inventors tried to assess the drug efficacy of anti-mouse NR 10 neutralizing antibodies in mouse models for various pathological conditions. The results demonstrated that the neutralizing antibodies produced the effect of markedly suppressing symptoms in atopic dermatitis model mice using NC/Nga mice, and in model mice for chronic dermatitis, which were developed by repeated application of picryl chloride. This proved that the neutralizing antibodies were actually useful as a therapeutic agent. In addition, the antibodies were demonstrated to produce the effect of suppressing symptoms in collagen arthritis, a model for rheumatism, and in collagenase arthritis, a model for osteoarthritis. These results suggest that the NR 10-neutralizing antibody of the present invention can be used to prevent or treat chronic inflammation. The present inventors also succeeded in obtaining human NR 10 neutralizing antibodies. Specifically, the present invention provides:

[1] an agent for preventing or treating an inflammatory disease, wherein the agent comprises an NR 10 antagonist as an active ingredient; [2] the preventive or therapeutic agent of [1], wherein the NR 10 antagonist is an antibody having an NR 10 neutralizing activity; [3] the preventive or therapeutic agent of [2], wherein the antibody is a monoclonal antibody; [4] the preventive or therapeutic agent of [2], wherein the antibody is a monoclonal antibody having a human NR 10 neutralizing activity; [5] the preventive or therapeutic agent of any one of [2] to [4], wherein the antibody is a recombinant antibody; [6] the preventive or therapeutic agent of [5], wherein the recombinant antibody is a chimeric antibody, humanized antibody, or human antibody; [7] the preventive or therapeutic agent of any one of [2] to [6], wherein the agent comprises as an active ingredient a fragment and/or a modified fragment of the antibody with NR 10 neutralizing activity; [8] the preventive or therapeutic agent of any one of [1] to [7], wherein the inflammatory disease is atopic dermatitis; [9] the preventive or therapeutic agent of any one of [1] to [7], wherein the inflammatory disease is chronic dermatitis; [10] the preventive or therapeutic agent of any one of [1] to [7], wherein the inflammatory disease is rheumatism; [11] the preventive or therapeutic agent of any one of [1] to [7], wherein the inflammatory disease is osteoarthritis; [12] an antibody having an NR 10 neutralizing activity; [13] the antibody of [12], which is a monoclonal antibody; [14] the antibody of [12], wherein NR 10 is human NR 10; [15] the antibody of any one of [12] to [14], which is a recombinant antibody; [16] the antibody of [15], wherein the recombinant antibody is a chimeric antibody, humanized antibody, or human antibody; [17] a fragment and/or a modified fragment of the antibody of any one of [12] to [16] [18] a method for preventing or treating an inflammatory disease, which comprises the step of administering an NR 10 antagonist to a patient with an inflammatory disease; and [19] use of an NR 10 antagonist to produce an agent for preventing or treating an inflammatory disease.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a graph showing a result obtained by observing the cell growth-suppressing effect of BM095 added to a cell growth assay system using IL-31-dependent Ba/F3 cells. The horizontal axis indicates estimated mIL-31 concentrations in the assay system, and the vertical axis indicates cell counts (OD450 (absorbance at 450 nm)). Amounts of BM095 added (unit: ng/ml) are shown in the legend. A cell-growth suppressing effect dependent on the amount of BM095 added was observed.

FIG. 2 is a graph showing a therapeutic effect produced when anti-NR 10 antibodies were administered to atopic dermatitis model mice. A significant inflammation-suppressing effect was seen in the anti-NR 10 antibody administered group as compared with the negative control group (vehicle group).

FIG. 3 is a graph showing a sequential change in body weight after anti-NR 10 antibodies were administered to atopic dermatitis model mice. Weight loss was observed in the group administered with an existing anti-inflammatory agent. In contrast, no weight change was detected in the anti-NR 10 antibody-administered group. Thus, the anti-NR 10 antibody was proven to be safe.

FIG. 4 is a graph showing a therapeutic effect produced when anti-NR 10 antibodies were administered to chronic dermatitis model mice. A significant auricle swelling-suppressing effect was found in the anti-NR 10 antibody-administered group.

FIG. 5 is a photograph showing immunohistochemical staining of the auricle of a chronic dermatitis model mouse. As with the case of humans, the expression of mouse NR 10 was found to be enhanced in thickened epidermis.

FIG. 6 is a graph showing an arthritis-suppressing effect produced when anti-NR 10 antibodies were administered to collagen-induced arthritis model mice.

FIG. 7 is a graph showing the relationship between the area under the curve (AUC) and the concentration of BM095 administered to the collagenase-induced arthritis (osteoarthritis) model. AUC means the area under the curve of transition of the difference between the right and left knee joint widths defined as a value representing swelling in the right knee joint.

FIG. 8 is a graph showing the correlation between the concentration of human NR 10 neutralizing antibodies (purified antibody) and cell growth-suppressing activity in the presence of IL-31. Antibodies 1, 2, and 3 exhibited strong NR 10-neutralizing activity.

FIG. 9 is a graph showing the correlation between the concentration of chimeric antibody NA633 against human NR 10 and cell growth-suppressing activity in the presence of IL-31. NA633 exhibited strong NR 10-neutralizing activity.

FIG. 10 is a diagram comparing the amino acid sequences of human NR 10 and NR 10 of a cynomolgus monkey. The double-underlined sequence indicates the transmembrane region.

FIG. 11 is a graph showing the cell growth-suppressing activity of the chimeric antibody NA633 in human-IL-31 stimulated cynomolgus monkey NR 10/human OSMR/BaF cell line. NA633 also showed cynomolgus monkey NR 10-neutralizing activity.

FIG. 12 is a graph showing the transition of percent body weight change in DSS colitis model mice.

FIG. 13 is a graph showing the transition of change in the thickness of the auricle in the acute contact dermatitis model using picryl chloride.

BEST MODE FOR CARRYING OUT THE INVENTION

The present invention relates to agents for preventing or treating inflammatory diseases, which comprise NR 10 antagonists as active ingredients. The present invention is based on the present inventors' finding that NR 10 antagonists (for example, anti-NR 10 neutralizing antibodies) significantly suppress symptoms in model mice with atopic dermatitis, chronic dermatitis, rheumatism, osteoarthritis or such.

NR 10 is a protein that forms a heterodimer with oncostatin M receptor (OSMR), and functions as an IL-31 receptor. NR 10 is also known by other names, such as glm-r (J Biol Chem 277, 16831-6, 2002), GPL (J Biol Chem 278, 49850-9, 2003), and IL-31RA (Nat Immunol 5, 752-60, 2004). The NR 10 of the present invention includes proteins called by such names. The NR 10 of the present invention also includes NR 10 derived from humans, mice, and other mammals. Preferred NR 10 includes human- and mouse-derived NR 10, but is not limited thereto. There are multiple known splicing variants of human-derived NR 10 (WO 00/075314). Of the above-described splicing variants, NR 10.1 consists of 662 amino acids and comprises a transmembrane domain. NR 10.2 is a soluble receptor-like protein consisting of 252 amino acids without the transmembrane domain. Meanwhile, known NR 10 splicing variants that function as transmembrane receptor proteins include NR 10.3 and IL-31RAv3. The human NR 10 of the present invention is not particularly limited, as long as it forms a heterodimer with oncostatin M receptor (OSMR) and functions as an IL-31 receptor. Preferred NR 10 includes NR 10.3 (also referred to as ILRAv4 (Nat Immunol 5, 752-60, 2004)) and IL-31RAv3. NR 10.3 (IL-31RAv4) consists of 662 amino acids (WO 00/075314; Nat Immunol 5, 752-60, 2004) and IL-31RAv3 consists of 732 amino acids (GenBank Accession No: NM_(—)139017). The amino acid sequence of IL-31RAv4 is shown in SEQ ID NO: 6, and the amino acid sequence of IL-31RAv3 is shown in SEQ ID NO: 7. Meanwhile, mouse-derived NR 10 includes proteins comprising the amino acid sequence of SEQ ID NO: 5.

The NR 10 antagonists of the present invention refer to substances that bind to NR 10 and block NR 10-activation-based intracellular signal transduction, thereby causing loss or suppression of physiological activities of cells. Herein, physiological activities include, for example, activities of inducing or suppressing the production of physiologically active substances (for example, chemokines and inflammatory cytokines), activities of enhancing or suppressing the secretion of the substances, growth activity, growth-inducing activity, survival activity, differentiation activity, differentiation-inducing activity, transcriptional activity, membrane transport activity, binding activity, proteolytic activity, phosphorylation/dephosphorylation activity, oxidation-reduction activity, transfer activity, nucleolytic activity, dehydration activity, cell-death-inducing activity, and apoptosis-inducing activity, but are not limited thereto.

The presence of antagonist activity can be determined by methods known to those skilled in the art. For example, test compounds are contacted with NR 10 expressed on the surface of cells in the presence of a ligand, and it is determined whether or not intracellular signal transduction, which is an indicator of NR 10 activation, is generated. Such a determination can be made, for example, by the method described in the document “Dillon S R, et al., Interleukin 31, a cytokine produced by activated T cells, induces dermatitis in mice. Nat. Immunol. 2004 July; 5(7):752-60”. Compounds that inhibit intracellular signal transduction in response to ligand stimulation are thought to serve as NR 10 antagonists.

The antagonists of the present invention may be natural or artificial compounds. Known compounds may be used as the antagonists of the present invention. Novel compounds determined to have antagonist activity by the methods described above may also be used.

In an embodiment of the present invention, the NR 10 antagonists include antibodies having the activity of neutralizing NR 10. The “antibodies having NR 10-neutralizing activity” of the present invention refer to antibodies having the activity of suppressing NR 10-based physiological activities. The “antibodies having NR 10-neutralizing activity” of the present invention may be polyclonal or monoclonal antibodies, and as a preferred embodiment, includes monoclonal antibodies.

Such monoclonal antibodies having NR 10-neutralizing activity, can be obtained, for example, by the following procedure: anti-NR 10 monoclonal antibodies are prepared by using as an antigen NR 10 or a fragment thereof that is derived from a mammal, such as human or mouse, by known methods, and then antibodies having NR 10-neutralizing activity are selected from the thus obtained anti-NR 10 monoclonal antibodies. Specifically, immunization is achieved by conventional immunization methods using as a sensitizing antigen a desired antigen or cells expressing the desired antigen. Anti-NR 10 monoclonal antibodies can be prepared by fusing the obtained immune cells with known parental cells using conventional cell fusion methods, and screening them for monoclonal antibody-producing cells (hybridomas) by conventional screening methods. Animals to be immunized include, for example, mammals, such as mice, rats, rabbits, sheep, monkeys, goats, donkeys, cows, horses, and pigs. The antigen can be prepared using the known NR 10 gene sequence according to known methods, for example, by methods using baculovirus (for example, WO 98/46777). As described in Examples herein below, antibodies having NR 10-neutralizing activity may be selected, for example, by testing the effect of suppressing the growth of an IL-31-dependent cell line after the candidate antibody is added to cells of the IL-31-dependent cell line. Antibodies that suppress the growth of IL-31-dependent cell line in the method described above are considered to have NR 10-neutralizing activity.

Hybridomas can be prepared, for example, according to the method of Milstein et al. (Kohler, G. and Milstein, C., Methods Enzymol. (1981) 73: 3-46) or such. When the immunogenicity of an antigen is low, immunization may be performed after linking the antigen with a macromolecule having immunogenicity, such as albumin.

In a preferred embodiment of the present invention, antibodies having NR 10-neutralizing activity include monoclonal antibodies having the activity of neutralizing human NR 10. There is no particular limitation on the immunogen for preparing monoclonal antibodies having the activity of neutralizing human NR 10, as long as it allows preparation of antibodies having the activity of neutralizing human NR 10. For example, multiple variants of human NR 10 are known to exist. Any of the variants may be used as immunogens, as long as it allows preparation of antibodies having human NR 10 neutralizing activity. Alternatively, a peptide fragment of NR 10 or a natural NR 10 sequence introduced with artificial mutations may be used as the immunogen under the same conditions. Human NR 10.3 is a preferred immunogen to prepare antibodies of the present invention that have NR 10-neutralizing activity.

Herein, the above-described antibodies of the present invention are not particularly limited, as long as they have NR 10-neutralizing activity. The antibodies also include recombinant antibodies such as chimeric antibodies, humanized antibodies, and human antibodies. The chimeric antibodies comprise, for example, the heavy and light chain constant regions of a human antibody, and the heavy and light chain variable regions of a non-human mammal, such as mouse. The chimeric antibodies can be produced by known methods. For example, the antibodies can be produced by cloning an antibody gene from hybridomas, inserting it into an appropriate vector, and introducing the construct into hosts (see, for example, Carl, A. K. Borrebaeck, James, W. Larrick, THERAPEUTIC MONOCLONAL ANTIBODIES, Published in the United Kingdom by MACMILLAN PUBLISHERS LTD, 1990). Specifically, cDNAs of the antibody variable regions (V regions) are synthesized from mRNA of hybridomas using reverse transcriptase. Once DNAs encoding the V regions of an antibody of interest are obtained, these are linked with DNAs encoding the constant regions (C regions) of a desired human antibody. The resulting constructs are inserted into expression vectors. Alternatively, the DNAs encoding the antibody V regions may be inserted into expression vectors comprising DNAs encoding the C regions of a human antibody. The DNAs are inserted into expression vectors so that they are expressed under the regulation of the expression regulatory regions, for example, enhancers and promoters. In the next step, host cells can be transformed with the expression vectors to allow expression of chimeric antibodies.

A humanized antibody, which is also called a reshaped human antibody, is obtained by transferring a complementarity determining region (CDR) of an antibody of a nonhuman mammal such as a mouse, with the CDR of a human antibody. Conventional genetic recombination techniques for the preparation of such antibodies are also known. Specifically, a DNA sequence designed to ligate a CDR of a mouse antibody with the framework regions (FRs) of a human antibody is synthesized by PCR, using several oligonucleotides constructed to comprise overlapping portions at their ends. A humanized antibody can be obtained by (1) ligating the resulting DNA to a DNA that encodes a human antibody constant region; (2) incorporating this into an expression vector; and (3) transfecting the vector into a host to produce the antibody (see European Patent Application No. EP 239,400 and International Patent Application Publication No. WO 96/02576). Human antibody FRs that are ligated via the CDR are selected where the CDR forms a favorable antigen-binding site. As necessary, amino acids in the framework region of an antibody variable region may be substituted such that the CDR of a reshaped human antibody forms an appropriate antigen-binding site (Sato, K. et al., Cancer Res. (1993) 53, 851-856).

Methods for obtaining human antibodies are also known. For example, desired human antibodies with antigen-binding activity can be obtained by (1) sensitizing human lymphocytes with antigens of interest or cells expressing antigens of interest in vitro; and (2) fusing the sensitized lymphocytes with human myeloma cells such as U266 (see Japanese Patent Application Kokoku Publication No. (JP-B) H01-59878 (examined, approved Japanese patent application published for opposition)). Alternatively, the desired human antibody can also be obtained by using a desired antigen to immunize a transgenic animal that comprises an entire repertoire of human antibody genes (see International Patent Application Publication Nos. WO 93/12227, WO 92/03918, WO 94/02602, WO 94/25585, WO 96/34096, and WO 96/33735).

Furthermore, techniques to obtain human antibodies by panning with a human antibody phage library are known. For example, the variable region of a human antibody is expressed as a single chain antibody (scFv) on the surface of a phage, using a phage display method, and phages that bind to the antigen can be selected. By analyzing the genes of selected phages, the DNA sequences encoding the variable regions of human antibodies that bind to the antigen can be determined. If the DNA sequences of scFvs that bind to the antigen are identified, appropriate expression vectors comprising these sequences can be constructed to obtain human antibodies. Such methods are well known (see WO 92/01047, WO 92/20791, WO 93/06213, WO 93/11236, WO 93/19172, WO 95/01438, and WO 95/15388).

The amino acid sequence of the heavy chain variable region or light chain variable region may be an amino acid sequence with a substitution, deletion, addition, and/or insertion of one or more amino acids in the amino acid sequence of the heavy chain variable region or light chain variable region of an antibody that has been confirmed to have NR 10-neutralizing activity, as long as NR 10-neutralizing activity is retained. Methods well known to those skilled in the art to prepare the amino acid sequence of the heavy chain variable region or light chain variable region of the antibody having NR 10-neutralizing activity, which comprises a substitution, deletion, addition, and/or insertion of one or more amino acids in the amino acid sequence of the heavy chain variable region or light chain variable region, include known methods for introducing mutations into proteins. For example, those skilled in the art can prepare mutants functionally equivalent to the heavy chain variable region or light chain variable region of the antibody having NR 10-neutralizing activity by introducing appropriate mutations into the amino acid sequence of the heavy chain variable region or light chain variable region of the antibody having NR 10-neutralizing activity using site-directed mutagenesis (Hashimoto-Gotoh, T, Mizuno, T, Ogasahara, Y, and Nakagawa, M. (1995) An oligodeoxyribonucleotide-directed dual amber method for site-directed mutagenesis. Gene 152, 271-275, Zoller, M J, and Smith, M. (1983) Oligonucleotide-directed mutagenesis of DNA fragments cloned into M13 vectors. Methods Enzymol. 100, 468-500, Kramer, W, Drutsa, V, Jansen, H W, Kramer, B, Pflugfelder, M, and Fritz, H J (1984) The gapped duplex DNA approach to oligonucleotide-directed mutation construction. Nucleic Acids Res. 12, 9441-9456, Kramer W, and Fritz H J (1987) Oligonucleotide-directed construction of mutations via gapped duplex DNA Methods. Enzymol. 154, 350-367, Kunkel, T A (1985) Rapid and efficient site-specific mutagenesis without phenotypic selection. Proc Natl Acad Sci USA. 82, 488-492) or the like. Thus, heavy chain variable regions or light chain variable regions that comprise mutations at one or more amino acids in the heavy chain variable region or light chain variable region of the antibody having NR 10-neutralizing activity are also included in the heavy chain variable region or light chain variable region of the present invention.

When an amino acid residue is altered, the amino acid is preferably mutated for a different amino acid(s) that conserves the properties of the amino acid side-chain. Examples of amino acid side chain properties are: hydrophobic amino acids (A, I, L, M, F, P, W, Y, and V), hydrophilic amino acids (R, D, N, C, E, Q, G, H, K, S, and T), amino acids comprising aliphatic side chains (G, A, V, L, I, and P), amino acids comprising hydroxyl group-containing side chains (S, T, and Y), amino acids comprising sulfur-containing side chains (C and M), amino acids comprising carboxylic acid- and amide-containing side chains (D, N, E, and Q), amino acids comprising basic side chains (R, K, and H), and amino acids comprising aromatic side chains (H, F, Y, and W) (amino acids are represented by one-letter codes in parentheses). Amino acid substitutions within each group are called conservative substitutions. It is already known that a polypeptide comprising a modified amino acid sequence in which one or more amino acid residues in a given amino acid sequence are deleted, added, and/or substituted with other amino acids can retain the original biological activity (Mark, D. F. et al., Proc. Natl. Acad. Sci. USA; (1984) 81:5662-6; Zoller, M. J. and Smith, M., Nucleic Acids Res. (1982) 10:6487-500; Wang, A. et al., Science (1984) 224:1431-3; Dalbadie-McFarland, G. et al., Proc. Natl. Acad. Sci. USA (1982) 79:6409-13). Such mutants comprise an amino acid sequence which is at least 70% identical to the amino acid sequence of a heavy chain variable region or light chain variable region of the present invention, more preferably at least 75%, even more preferably at least 80%, still more preferably at least 85%, yet more preferably at least 90%, and most preferably at least 95% identical. Herein, sequence identity is defined as the percentage of residues identical to those in the original amino acid sequence of the heavy chain variable region or light chain variable region, determined after the sequences are aligned and gaps are appropriately introduced to maximize the sequence identity as necessary. The identity of amino acid sequences can be determined by the method described above.

Alternatively, an amino acid sequence of the heavy chain variable region or light chain variable region that comprises a substitution, deletion, addition, and/or insertion of one or more amino acids in the amino acid sequence of the heavy chain variable region or light chain variable region and retains NR 10-neutralizing activity can be obtained from nucleic acid that hybridizes under stringent conditions to nucleic acid comprising the nucleotide sequence encoding the amino acid sequence of the heavy chain variable region or light chain variable region. Stringent hybridization conditions to isolate a nucleic acid that hybridizes under stringent conditions to a nucleic acid that comprises the nucleotide sequence encoding the amino acid sequence of the heavy chain variable region or light chain variable region include, for example, the conditions of 6M urea, 0.4% SDS, 0.5×SSC, and 37° C., or hybridization conditions with stringencies equivalent thereto. With more stringent conditions, for example, the conditions of 6M urea, 0.4% SDS, 0.1×SSC, and 42° C., isolation of nucleic acids with a much higher homology can be expected. The sequences of the isolated nucleic acids can be determined by the known methods described below. The overall nucleotide sequence homology of the isolated nucleic acid is at least 50% or higher sequence identity, preferably 70% or higher, more preferably 90% or higher (for example, 95%, 96%, 97%, 98%, 99%, or higher).

A nucleic acid that hybridizes under stringent conditions to a nucleic acid comprising the nucleotide sequence encoding the amino acid sequence of the heavy chain variable region or light chain variable region can also be isolated using, instead of the above-described methods using hybridization techniques, gene amplification methods using primers synthesized based on the information of nucleotide sequence encoding the amino acid sequence of the heavy chain variable region or light chain variable region, for example, polymerase chain reaction (PCR).

Specifically, the identity of one nucleotide sequence or amino acid sequence to another can be determined using the algorithm BLAST, by Karlin and Altschul (Proc. Natl. Acad. Sci. USA (1993) 90, 5873-7). Programs such as BLASTN and BLASTX were developed based on this algorithm (Altschul et al., J. Mol. Biol. (1990) 215, 403-10). To analyze nucleotide sequences according to BLASTN based on BLAST, the parameters are set, for example, as score=100 and wordlength=12. On the other hand, parameters used for the analysis of amino acid sequences by BLASTX based on BLAST include, for example, score=50 and wordlength=3. Default parameters for each program are used when using the BLAST and Gapped BLAST programs. Specific techniques for such analyses are known in the art (see the website of the National Center for Biotechnology Information (NCBI), Basic Local Alignment Search Tool (BLAST); http://www.ncbi.nlm.nih.gov).

Alternatively, the antibodies of the present invention may be minibodies. Such minibodies of the present invention include antibody fragments lacking some portions of a whole antibody (for example, whole IgG), and are not particularly limited as long as they retain NR 10-neutralizing activity. The minibodies of the present invention are not particularly limited, as long as they are portions of whole antibodies. The minibodies preferably comprise a heavy chain variable region (VH) or light chain variable region (VL). Particularly preferred minibodies comprise both VH and VL.

The minibodies of the present invention preferably have a smaller molecular weight than whole antibodies. However, the minibodies may form multimers, for example, dimers, trimers, or tetramers, and thus their molecular weights can be greater than those of whole antibodies.

The minibodies of the present invention include, for example, scFv antibodies. ScFv antibodies are single-chain polypeptides constructed by linking a heavy chain variable region ([VH]) and a light chain variable region ([VL]) via a linker or such (Huston, J. S. et al., Proc. Natl. Acad. Sci. U.S.A. (1988) 85, 5879-5883; Plickthun “The Pharmacology of Monoclonal Antibodies” Vol. 113, eds., Resenburg and Moore, Springer Verlag, New York, pp. 269-315, (1994)). The order of the heavy chain variable region and light chain variable region to be linked together is not particularly limited, and they may be arranged in any order. Examples of the arrangements are listed below.

[VH] linker [VL] [VL] linker [VH]

The amino acid sequence of the heavy chain variable region or light chain variable region may comprise a substitution, deletion, addition, and/or insertion. Furthermore, the heavy chain variable region and light chain variable region may also lack some portions or be added with other polypeptides, as long as they have antigen binding ability when linked together. Alternatively, the variable regions may be chimerized or humanized.

In the present invention, linkers which bind the variable region of the antibody comprise arbitrary peptide linkers that can be introduced using genetic engineering, or synthetic linkers (for example, linkers disclosed in “Protein Engineering, 9(3), 299-305, 1996”).

The preferred linkers in the present invention are peptide linkers. The lengths of the peptide linkers are not particularly limited and those skilled in the art can appropriately select the lengths depending on the purpose. Typical lengths are one to 100 amino acids, preferably 3 to 50 amino acids, more preferably 5 to 30 amino acids, and particularly preferably 12 to 18 amino acids (for example, 15 amino acids).

Amino acid sequences of such peptide linkers include, for example:

Ser Gly•Ser Gly•Gly•Ser Ser•Gly•Gly Gly•Gly•Gly•Ser (SEQ ID NO: 8) Ser•Gly•Gly•Gly (SEQ ID NO: 9) Gly•Gly•Gly•Gly•Ser (SEQ ID NO: 10) Ser•Gly•Gly•Gly•Gly (SEQ ID NO: 11) Gly•Gly•Gly•Gly•Gly•Ser (SEQ ID NO: 12) Ser•Gly•Gly•Gly•Gly•Gly (SEQ ID NO: 13) Gly•Gly•Gly•Gly•Gly•Gly•Ser (SEQ ID NO: 14) Ser•Gly•Gly•Gly•Gly•Gly•Gly (SEQ ID NO: 15) (Gly•Gly•Gly•Gly•Ser (SEQ ID NO: 10))n (Ser•Gly•Gly•Gly•Gly (SEQ ID NO: 11))n where n is an integer of 1 or larger.

Synthetic linkers (chemical crosslinking agents) include crosslinking agents that are routinely used to crosslink peptides, for example, N-hydroxy succinimide (NHS), disuccinimidyl suberate (DSS), bis(succinimidyl) suberate (BS³), dithiobis(succinimidyl propionate) (DSP), dithiobis(succinimidyl propionate) (DTSSP), ethylene glycol bis(succinimidyl succinate) (EGS), ethylene glycol bis(sulfosuccinimidyl succinate) (sulfo-EGS), disuccinimidyl tartrate (DST), disulfosuccinimidyl tartrate (sulfo-DST), bis[2-(succinimidoxycarbonyloxy)ethyl]sulfone (BSOCOES), and bis[2-(succinimidoxycarbonyloxy)ethyl]sulfone (sulfo-BSOCOES). These crosslinking agents are commercially available.

Antibodies of the present invention include antibodies in which two or more amino acid residues have been added to the amino acid sequence of an antibody of the present invention. Further, fusion proteins which result from a fusion between one of the above antibodies and a second peptide or protein is included in the present invention. The fusion proteins can be prepared by ligating a polynucleotide encoding an antibody of the present invention and a polynucleotide encoding a second peptide or polypeptide in frame, inserting this into an expression vector, and expressing the fusion construct in a host. Some techniques known to those skilled in the art are available for this purpose. The partner peptide or polypeptide to be fused with an antibody of the present invention may be a known peptide, for example, FLAG (Hopp, T. P. et al., BioTechnology 6, 1204-1210 (1988)), 6×His consisting of six His (histidine) residues, 10×His, influenza hemagglutinin (HA), human c-myc fragment, VSV-GP fragment, p18HIV fragment, T7-tag, HSV-tag, E-tag, SV40 T antigen fragment, lck tag, α-tubulin fragment, B-tag, Protein C fragment. Other partner polypeptides to be fused with the antibodies of the present invention include, for example, GST (glutathione-S-transferase), HA (influenza hemagglutinin), immunoglobulin constant region, β-galactosidase, and MBP (maltose-binding protein). A polynucleotide encoding one of these commercially available peptides or polypeptides can be fused with a polynucleotide encoding an antibody of the present invention. The fusion polypeptide can be prepared by expressing the fusion construct.

The antibodies of the present invention may differ in amino acid sequence, molecular weight, isoelectric point, presence/absence of sugar chains, and conformation depending on the cell or host producing the antibody, or purification method. However, a resulting antibody is included in the present invention, as long as it is functionally equivalent to an antibody of the present invention. For example, when an antibody of the present invention is expressed in prokaryotic cells, for example E. coli, a methionine residue is added to the N terminus of the original antibody amino acid sequence. Such antibodies are included in the present invention.

The antibody of the present invention can be prepared by methods known to those skilled in the art. The antibody can be prepared, for example, by genetic recombination techniques known to those skilled in the art based on the sequence of an antibody that recognizes NR 10. Specifically, such antibody can be prepared by constructing a polynucleotide encoding an antibody based on the sequence of an antibody that recognizes NR 10, inserting the construct into an expression vector, and then expressing it in appropriate host cells (see for example, Co, M. S. et al., J. Immunol. (1994) 152, 2968-2976; Better, M. and Horwitz, A. H., Methods Enzymol. (1989) 178, 476-496; Pluckthun, A. and Skerra, A., Methods Enzymol. (1989) 178, 497-515; Lamoyi, E., Methods Enzymol. (1986) 121, 652-663; Rousseaux, J. et al., Methods Enzymol. (1986) 121, 663-669; Bird, R. E. and Walker, B. W., Trends Biotechnol. (1991) 9, 132-137).

The vectors include M13 vectors, pUC vectors, pBR322, pBluescript, and pCR-Script. Alternatively, when aiming to subclone and excise cDNA, the vectors include, for example, pGEM-T, pDIRECT, and pT7, in addition to the vectors described above. Expression vectors are particularly useful when using vectors for producing the antibodies of the present invention. For example, when aiming for expression in E. coli such as JM109, DH5α, HB101, and XL1-Blue, the expression vectors not only have the above-described characteristics that allow vector amplification in E. coli, but must also carry a promoter that allows efficient expression in E. coli, for example, lacZ promoter (Ward et al., Nature (1989) 341, 544-546; FASEB J. (1992) 6, 2422-2427), araB promoter (Better et al., Science (1988) 240, 1041-1043), T7 promoter or such. Such vectors include pGEX-5X-1 (Pharmacia), “QIAexpress system” (Quiagen), pEGFP, or pET (in this case, the host is preferably BL21 that expresses T7 RNA polymerase) in addition to the vectors described above.

The vectors may comprise signal sequences for antibody secretion. As a signal sequence for antibody secretion, a pelB signal sequence (Lei, S. P. et al J. Bacteriol. (1987) 169, 4379) may be used when a protein is secreted into the E. coli periplasm. The vector can be introduced into host cells by calcium chloride or electroporation methods, for example.

In addition to vectors for E. coli, the vectors for producing the antibodies of the present invention include mammalian expression vectors (for example, pcDNA3 (Invitrogen), pEF-BOS (Nucleic Acids. Res. 1990, 18(17), p 5322), pEF, and pCDM8), insect cell-derived expression vectors (for example, the “Bac-to-BAC baculovirus expression system” (Gibco-BRL) and pBacPAK8), plant-derived expression vectors (for example, pMH1 and pMH2), animal virus-derived expression vectors (for example, pHSV, pMV, and pAdexLcw), retroviral expression vectors (for example, pZIPneo), yeast expression vectors (for example, “Pichia Expression Kit” (Invitrogen), pNV11, and SP-Q01), and Bacillus subtilis expression vectors (for example, pPL608 and pKTH50), for example.

When aiming for expression in animal cells such as CHO, COS, and NIH3T3 cells, the vectors must have a promoter essential for expression in cells, for example, SV40 promoter (Mulligan et al., Nature (1979) 277, 108), MMLV-LTR promoter, EF1α promoter (Mizushima et al., Nucleic Acids Res. (1990) 18, 5322), and CMV promoter, and more preferably they have a gene for selecting transformed cells (for example, a drug resistance gene that allows evaluation using an agent (neomycin, G418, or such). Vectors with such characteristics include pMAM, pDR2, pBK-RSV, pBK-CMV, pOPRSV, and pOP13, for example.

In addition, the following method can be used for stable gene expression and gene amplification in cells: CHO cells deficient in a nucleic acid synthesis pathway are introduced with a vector (for example, pSV2-dhfr (Molecular Cloning 2^(nd) edition, Cold Spring Harbor Laboratory Press, 1989)) that carries a DHFR gene which compensates for the deficiency, and the vector is amplified using methotrexate (MTX). Alternatively, the following method can be used for transient gene expression: COS cells with a gene expressing SV40 T antigen on their chromosome are transformed with a vector (pcD and such) with an SV40 replication origin. Replication origins derived from polyoma virus, adenovirus, bovine papilloma virus (BPV), and such can also be used. To amplify gene copy number in host cells, the expression vectors may further carry selection markers such as aminoglycoside transferase (APH) gene, thymidine kinase (TK) gene, E. coli xanthine-guanine phosphoribosyltransferase (Ecogpt) gene, and dihydrofolate reductase (dhfr) gene.

Desired antibodies obtained by the methods described above can be isolated from inside host cells or from outside the cells (the medium, or such), and purified to homogeneity. The antibodies can be isolated and purified by methods routinely used for isolating and purifying antibodies, and the type of method is not limited. For example, the antibodies can be isolated and purified by appropriately selecting and combining column chromatography, filtration, ultrafiltration, salting out, solvent precipitation, solvent extraction, distillation, immunoprecipitation, SDS-polyacrylamide gel electrophoresis, isoelectrofocusing, dialysis, recrystallization, and such.

The chromatographies include, for example, affinity chromatography, ion exchange chromatography, hydrophobic chromatography, gel filtration, reverse phase chromatography, and adsorption chromatography (Strategies for Protein Purification and Characterization: A Laboratory Course Manual. Ed Daniel R. Marshak et al., Cold Spring Harbor Laboratory Press, 1996). The chromatographic methods described above can be conducted using liquid chromatography, for example, HPLC and FPLC. Columns that can be used for affinity chromatography include protein A columns and protein G columns. Columns using protein A include, for example, Hyper D, POROS, and Sepharose FF (GE Amersham Biosciences). The present invention comprises antibodies that are highly purified using these purification methods.

The present invention also provides agents for preventing or treating inflammatory diseases, which comprise as active ingredients fragments and/or modification products of an antibody of the present invention. The fragments and/or modification products of antibodies of the present invention include antibody fragments lacking some portions of the antibodies of the present invention (whole antibodies (for example, whole IgG), recombinant antibodies (for example, chimeric antibodies, humanized antibodies, and human antibodies), and minibodies (for example, scFv antibodies)), and are not particularly limited as long as they retain the ability to bind to their antigens. The antibody fragments of the present invention are not particularly limited, as long as they are portions of whole antibodies. The fragments preferably comprise a heavy chain variable region (VH) and/or a light chain variable region (VL). The amino acid sequence of the VH or VL may comprise substitutions, deletions, additions, and/or insertions. The VH and/or VL may lack some portions, as long as the ability to bind to the antigen is retained. Furthermore, the variable region may be chimerized or humanized. Specifically, antibody fragments include, for example, Fab, Fab′, F(ab′)2, and Fv. Such antibody fragments can be obtained by constructing genes encoding the antibody fragments, introducing them into expression vectors, and then expressing them in appropriate host cells (see for example, Co, M. S. et al., J. Immunol. (1994) 152, 2968-2976; Better, M. and Horwitz, A. H., Methods Enzymol. (1989) 178, 476-496; Pluckthun, A. and Skerra, A., Methods Enzymol. (1989) 178, 497-515; Lamoyi, E., Methods Enzymol. (1986) 121, 652-663; Rousseaux, J. et al., Methods Enzymol. (1986) 121, 663-669; Bird, R. E. and Walker, B. W., Trends Biotechnol. (1991) 9, 132-137).

Furthermore, the antibodies of the present invention may be conjugated antibodies which are linked to any of various molecules, such as polyethylene glycol (PEG), radioactive substances, fluorescent substances, luminescent substances, enzymes, and toxins. Such conjugated antibodies can be obtained by chemically modifying the obtained antibodies. Methods for modifying antibodies have been established in this field (for example, U.S. Pat. No. 5,057,313 and U.S. Pat. No. 5,156,840). The “antibodies” of the present invention also include such conjugated antibodies.

The antibody's activity of binding to NR 10 can be determined by methods known to those skilled in the art. Methods for determining the antigen-binding activity of an antibody include, for example, ELISA (enzyme-linked immunosorbent assay), EIA (enzyme immunoassay), RIA (radioimmunoassay), and fluorescent antibody method. For example, when enzyme immunoassay is used, antibody-containing samples, such as purified antibodies and culture supernatants of antibody-producing cells, are added to antigen-coated plates. A secondary antibody labeled with an enzyme, such as alkaline phosphatase, is added and the plates are incubated. After washing, an enzyme substrate, such as p-nitrophenyl phosphate, is added, and the absorbance is measured to evaluate the antigen-binding activity.

Furthermore, the NR 10-neutralizing activity of an antibody can be determined, for example, by the method described in Examples, which involves testing the effect of suppressing the growth of the IL-31-dependent cell line.

The NR 10 antagonists or antibodies having NR 10-neutralizing activity of the present invention can be used in the agents for preventing or treating inflammatory diseases. The present inventors proved that administration of mouse NR 10 neutralizing antibodies produced marked therapeutic effects in model animals for various inflammatory diseases. Furthermore, the expression of human NR 10 has been reported to be enhanced in thickened epidermis of atopic dermatitis patients (Non-patent Document 1). The present inventors confirmed by immunohistochemical staining that, as with the case of humans, the expression of mouse NR 10 was enhanced in thickened epidermis of auricles in the above-described chronic dermatitis model mice (Example 5). These findings suggest that NR 10 is similarly involved in inflammatory diseases in all animal species, and that, like mouse NR 10 neutralizing antibodies, antibodies neutralizing human NR 10 are effective in preventing and treating various inflammatory diseases. Furthermore, as with the findings described in this Example, NR 10 antagonists other than antibodies are also expected to have therapeutic effects on various inflammatory diseases.

In the present invention, inflammatory disease refers to diseases with pathological features involved in cytological and histological reactions that occur in affected blood vessels and adjacent tissues in response to an injury or abnormal stimulation caused by physical, chemical, or biological agents (Stedman's Medical Dictionary, 5th Ed., MEDICAL VIEW CO., 2005). Generally, inflammatory diseases include, dermatitis (atopic dermatitis, chronic dermatitis, and such), inflammatory bowel diseases (colitis and such), asthma, arthritis (rheumatoid arthritis, osteoarthritis, and such), bronchitis, Th2 autoimmune diseases, systemic lupus erythematosus, myasthenia gravis, chronic GVHD, Crohn's disease, spondylitis deformans, lumbar pain, gout, inflammation after surgery or injury, swelling, neuralgia, laryngopharyngitis, cystitis, hepatitis (non-alcoholic steatohepatitis, alcoholic hepatitis, and such), hepatitis B, hepatitis C, and arteriosclerosis.

Preferred examples of inflammatory diseases that are subjects of the present invention include atopic dermatitis, chronic dermatitis, rheumatism, osteoarthritis, and chronic asthma.

The present inventors discovered that NR 10 antagonist antibodies have therapeutic effects against atopic dermatitis, chronic dermatitis, rheumatism, and osteoarthritis. On the other hand, it was revealed that NR 10 antagonist antibodies do not produce therapeutic effects in acute contact dermatitis and DSS acute colitis models.

The agents for preventing or treating inflammatory diseases of the present invention comprise as an active ingredient an NR 10 antagonist or an antibody having NR 10-neutralizing activity described above. The phrase “comprises an NR 10 antagonist as an active ingredient” means comprising an NR 10 antagonist as at least one of the active ingredients, and does not limit the contents. In addition, the agents for preventing or treating inflammatory diseases of the present invention may also comprise, in combination with an NR 10 antagonist, other ingredients that enhance the prevention or treatment of the inflammatory disease.

The NR 10 antagonist of the present invention can be formulated according to standard methods (see, for example, Remington's Pharmaceutical Science, latest edition, Mark Publishing Company, Easton, USA). Further, they may comprise pharmaceutically acceptable carriers and/or additives if necessary. For example, they may contain surfactants (for example, PEG and Tween), excipients, antioxidants (for example, ascorbic acid), coloring agents, flavoring agents, preservatives, stabilizers, buffering agents (for example, phosphoric acid, citric acid, and other organic acids), chelating agents (for example, EDTA), suspending agents, isotonizing agents, binders, disintegrators, lubricants, fluidity promoters, and corrigents. However, the carriers that can be comprised in the agents for preventing or treating inflammatory diseases of the present invention are not limited to this list. In fact, other commonly used carriers such as light anhydrous silicic acid, lactose, crystalline cellulose, mannitol, starch, carmelose calcium, carmelose sodium, hydroxypropylcellulose, hydroxypropylmethylcellulose, polyvinylacetaldiethylaminoacetate, polyvinylpyrrolidone, gelatin, medium chain fatty acid triglyceride, polyoxyethylene hydrogenated castor oil 60, sucrose, carboxymethylcellulose, corn starch, inorganic salt, and so on, can be appropriately comprised. The compositions may also comprise other low-molecular-weight polypeptides, proteins such as serum albumin, gelatin, and immunoglobulin, and amino acids such as glycine, glutamine, asparagine, arginine, and lysine. When the composition is prepared as an aqueous solution for injection, NR 10 antagonists may be dissolved in an isotonic solution comprising, for example, physiological saline, dextrose, and other adjuvants. The adjuvants may include, for example, D-sorbitol, D-mannose, D-mannitol, and sodium chloride. In addition, appropriate solubilizing agents, for example, alcohols (for example, ethanol), polyalcohols (for example, propylene glycols and PEGs), and non-ionic detergents (polysorbate 80 and HCO-50) may be used concomitantly.

If necessary, NR 10 antagonists may be encapsulated in microcapsules (microcapsules made of hydroxycellulose, gelatin, polymethylmethacrylate, and the like), and made into components of colloidal drug delivery systems (liposomes, albumin microspheres, microemulsions, nano-particles, and nano-capsules) (for example, see “Remington's Pharmaceutical Science 16th edition” &, Oslo Ed. (1980)). Moreover, methods for making sustained-release drugs are known, and these can be applied for NR 10 antagonists (Langer et al., J. Biomed. Mater. Res. (1981) 15, 167-277; Langer, Chem. Tech. (1982) 12, 98-105; U.S. Pat. No. 3,773,919; European Patent Application (EP) No. 58,481; Sidman et al., Biopolymers (1983) 22, 547-56; EP 133,988).

The agents for preventing or treating inflammatory diseases of the present invention can be administered either orally or parenterally, but are preferably administered parenterally. Specifically, the agents are administered to patients by injection or percutaneous administration. Injections include, for example, intravenous injections, intramuscular injections, and subcutaneous injections, for systemic or local administration. The agents may be given to sites where inflammation is to be suppressed, or areas surrounding the sites by local infusion, intramuscular injection in particular. The administration methods can be properly selected according to the patient's age and condition. The single-administration dose can be selected, for example, from within the range of 0.0001 to 100 mg of the active ingredient per kg body weight. Alternatively, when the agents are administered to human patients, the dose of the active ingredient can be selected from within the range of 0.001 to 1,000 mg/kg body weight. The single-administration dose preferably comprises, for example, NR 10 antagonist at about 0.01 to 50 mg/kg body weight. However, the dose of an agent for preventing or treating inflammatory diseases of the present invention is not limited to these examples.

The present invention also provides antibodies having NR 10-neutralizing activity (including fragments of antibodies having NR 10-neutralizing activity, and/or modification products thereof, the same definition is used throughout the description below). The antibodies having NR 10-neutralizing activity of the present invention are useful as active ingredients in the above-described agents for preventing or treating inflammatory diseases. The antibodies having NR 10-neutralizing activity of the present invention may be polyclonal or monoclonal antibodies, but are preferably monoclonal antibodies. Such monoclonal antibodies having NR 10-neutralizing activity can be obtained by the methods described above. The monoclonal antibodies of the present invention have the activity of neutralizing NR 10 derived from mammals or fragments thereof, preferably have the activity of neutralizing NR 10 derived from humans or mice, or fragments thereof, and more preferably the activity of neutralizing NR 10 derived from humans or fragments thereof. Human NR 10 or a peptide fragment thereof may be used as an immunogen to prepare monoclonal antibodies having the activity of neutralizing human NR 10. Alternatively, the antibodies having NR 10-neutralizing activity of the present invention may be recombinant antibodies. Recombinant antibodies having NR 10-neutralizing activity of the present invention include, but are not limited to, chimeric antibodies, humanized antibodies, human antibodies, and minibodies.

In the present invention, the antibodies having NR 10-neutralizing activity include, for example, anti-mouse NR 10 antibodies that comprise a heavy chain variable region comprising the amino acid sequence of SEQ ID NO: 1 and a light chain variable region comprising the amino acid sequence of SEQ ID NO: 3.

The present invention also includes monoclonal antibodies having the activity of neutralizing human NR 10. The monoclonal antibodies having the activity of neutralizing human NR 10 of the present invention can be obtained by preparing monoclonal antibodies using human NR 10 or a peptide fragment thereof as an immunogen, and then selecting from the anti-human NR 10 monoclonal antibodies, antibodies that have the activity of neutralizing human NR 10, based on the above-described assay system using the IL-31-dependent cell line.

In the present invention, the antibodies having the activity of neutralizing human NR 10 include the antibodies described in any one of:

(a) antibodies having a heavy chain variable region comprising CDR1, CDR2, and CDR3 that consist of the amino acid sequences of SEQ ID NOs: 18, 19, and 20, respectively. (b) antibodies having a light chain variable region comprising CDR1, CDR2, and CDR3 that consist of the amino acid sequences of SEQ ID NOs: 21, 22, and 23, respectively; (c) antibodies having the heavy chain variable region of (a) and the light chain variable region of (b); and (d) antibodies that recognize the same epitope as that recognized by the antibodies of any one of (a) to (c).

Whether an antibody recognizes the same epitope as that recognized by another antibody can be confirmed by the competition between the two antibodies against the epitope. Competition between the antibodies can be evaluated by competitive binding assays using means such as ELISA, fluorescence energy transfer method (FRET), and fluorometric microvolume assay technology (FMAT(R)). The amount of antibodies bound to an antigen indirectly correlate with the binding ability of candidate competitor antibodies (test antibodies) that competitively bind to the same epitope. In other words, as the amount of or the affinity of test antibodies against the same epitope increases, the amount of antibodies bound to the antigen decreases, and the amount of test antibodies bound to the antigen increases. Specifically, appropriately labeled antibodies and antibodies to be evaluated are simultaneously added to the antigens, and the thus bound antibodies are detected using the label. The amount of antibodies bound to the antigen can be easily determined by labeling the antibodies beforehand. This label is not particularly limited, and the labeling method is selected according to the assay technique used. The labeling method includes fluorescent labeling, radiolabeling, enzymatic labeling, and such.

For example, fluorescently labeled antibodies and unlabeled antibodies or test antibodies are simultaneously added to animal cells expressing NR 10, and the labeled antibodies are detected by fluorometric microvolume assay technology.

IC₅₀ is the concentration in which the amount of labeled antibodies bound to the epitope is reduced to 50% by the binding of unlabeled antibodies. Herein, antibodies that recognize the same epitope are antibodies that can reduce the amount of labeled antibodies bound to the epitope to at least 50% when the concentration of test antibodies is ten times higher than the IC₅₀ of the unlabeled antibodies.

Antibodies having the activity of neutralizing human NR 10 that are used in the present invention preferably further have binding activity to cynomolgus monkey NR 10, and more preferably have the activity of neutralizing cynomolgus monkey NR 10. The cynomolgus monkey NR 10 comprising the amino acid sequence of SEQ ID NO: 24 can be used in measurements of the activity of neutralizing or binding to cynomolgus monkey NR 10.

The present invention also provides the therapeutic methods described below. The interpretation of NR 10, antagonists, monoclonal antibodies, recombinant antibodies, inflammatory diseases, and others in the methods are as described above.

(1) a method for preventing or treating an inflammatory disease, which comprises the step of administering an NR 10 antagonist to a patient with an inflammatory disease; (2) the method of (1), in which the NR 10 antagonist is an antibody having the activity of binding to NR 10; (3) the method of (2), in which the antibody is a monoclonal antibody; (4) the method of (2), in which the antibody is a monoclonal antibody that binds to human NR 10; (5) the method of any one of (2) to (4), in which the antibody is a recombinant antibody; (6) the method of (5), in which the recombinant antibody is a chimeric antibody, humanized antibody, or human antibody; (7) the method of any one of (2) to (6), in which a fragment of an antibody having NR 10-neutralizing activity and/or a modified product thereof are included as an active ingredient; (8) the method of any one of (1) to (7), in which the inflammatory disease is atopic dermatitis; (9) the method of any one of (1) to (7), in which the inflammatory disease is chronic dermatitis; (10) the method of any one of (1) to (7), in which the inflammatory disease is rheumatism; and (11) the method of any one of (1) to (7), in which the inflammatory disease is osteoarthritis.

The present invention also provides the inventions described below. The explanation of NR 10, antagonists, monoclonal antibodies, recombinant antibodies, inflammatory diseases, and others in the methods are as described above.

(1) use of an NR 10 antagonist to produce an agent for preventing or treating an inflammatory disease; (2) the use of (1), in which the NR 10 antagonist is an antibody having the activity of binding to NR 10; (3) the use of (2), in which the antibody is a monoclonal antibody; (4) the use of (2), in which the antibody is a monoclonal antibody that binds to human NR 10; (5) the use of any one of (2) to (4), in which the antibody is a recombinant antibody; (6) the use of (5), in which the recombinant antibody is a chimeric antibody, humanized antibody, or human antibody; (7) the use of any one of (2) to (6), in which a fragment of an antibody having NR 10-neutralizing activity and/or a modification product thereof are included as an active ingredient; (8) the use of any one of (1) to (7), in which the inflammatory disease is atopic dermatitis; (9) the use of any one of (1) to (7), in which the inflammatory disease is chronic dermatitis; (10) the use of any one of (1) to (7), in which the inflammatory disease is rheumatism; and (11) the use of any one of (1) to (7), in which the inflammatory disease is osteoarthritis.

All prior-art documents cited herein are incorporated by reference herein.

EXAMPLES

Herein below, the present invention will be specifically described with reference to Examples, but it is not to be construed as being limited thereto.

Example 1 Establishment of Ba/F3 Cell Line that Express NR 10 and OSMR

A human NR 10 cDNA (SEQ ID NO: 1 of WO 0075314) was inserted into the expression vector pCOS1 (Biochem Biophys Res Commun. 228, p 838-45, 1996) to produce pCosNR 10.3. An oncostatin M receptor cDNA (OSMR, GenBank accession No. NM003999) was isolated from a human placental library by PCR, and then the expression vector pCos1-hOSMR was similarly constructed. By electroporation, 10 μg each of the vectors were simultaneously introduced into cells of the cell line Ba/F3 derived from mouse IL-3-dependent pro-B cells (BioRad Gene Pulser; 960 μF and 0.33 kV). After introduction, human IL-31 was added and the cells were cultured. Thus, a cell line that proliferated in an IL-31-dependent fashion was obtained. Likewise, a mouse-IL-31-dependent cell line was also prepared from Ba/F3 cells that were made to express the mouse NR 10 and OSMR genes.

In both cell lines, ED50 was found to be several ng/ml. Thus, well-proliferating cell lines were obtained. The human-IL-31-dependent cell line exhibited no response to mouse IL-31, and the growth was suppressed upon addition of human NR 10 protein (extracellular domain). The mouse-IL-31-dependent cell line exhibited no response to human IL-31, and the growth was not suppressed by the added mouse NR 10 protein (extracellular domain).

Example 2 Preparation of NR 10 Protein (Extracellular Domain)

The extracellular domain alone was amplified by PCR using NR 10 cDNA as a template, a FLAG tag sequence was attached to the C terminus, and was inserted into the expression vector pCXND3 (WO 2005/005636) (pCXND3-NR 10-flag). 10 μg of this linear vector was introduced into cells of Chinese hamster ovary cell line DG44 by electroporation (BioRad Gene PulserII; 25° F. and 1.5 kV). A high expression cell line was obtained. A purified sample was prepared from a supernatant of large-scale culture of the cell line by anti-FLAG antibody column (SIGMA) and gel filtration, and used in the experiments described below. Mouse NR 10 (extracellular domain) with FLAG tag sequence attached to the C terminus was similarly prepared.

Example 3 Isolation of scFv Having Anti-Mouse NR 10 Neutralizing Activity, and Preparation of BM095 as a Chimerized IgG

Specifically, the present inventors tried to narrow down the candidate clones from a human antibody phage library by panning using biotinylated mouse NR 10 protein (extracellular domain). Secretory scFv were purified from the clones, and added to the cell growth assay system using IL-31-dependent Ba/F3 cells described in Example 1. As a result, the clone BM095 exhibiting strong growth-suppressing activity was successfully obtained.

Using PCR, the human H chain variable region (VH) sequence of BM095 was linked to mouse IgG2a constant region (after CHI), and human L chain variable region (VL) sequence of BM095 was linked to mouse λ chain constant region, to construct an expression vector. The amino acid sequence of the VH is shown in SEQ ID NO: 1, and the nucleotide sequence encoding the amino acid sequence is shown in SEQ ID NO: 2. The amino acid sequence of the VL is shown in SEQ ID NO: 3, and the nucleotide sequence encoding the amino acid sequence is shown in SEQ ID NO: 4. The respective linear expression vectors were simultaneously introduced into the cell line DG44, and then a cell line expressing chimerized IgG at a high level was selected. A purified sample was obtained from a supernatant of a large-scale culture of this cell line using a protein A (rProtein A Sepharose Fast Flow, GE Amersham Biosciences) column and cation-exchange column chromatography (SP-TOYOPEARL 650M, TOSOH). Furthermore, pyrogen was removed using ActiClean Etox (Sterogen) resin to reduce the concentration to below the detection limit. The sample was used in the animal experiments described below. A result obtained by adding BM095 to the assay system described above is shown in FIG. 1.

Example 4 Assessment of Drug Efficacy in an Atopic Dermatitis Model Using NC/Nga Mice

A dermatitis model was produced by repeated application of picryl chloride (PiCl) at weekly intervals. Specifically, 4 days after sensitization with 5% PiCl (150 μl) on the abdomen and footpad, the induction of dermatitis was achieved by repeated application of 0.8% PiCl (150 μl) on the back and auricle at weekly intervals. The resulting symptoms were observed twice a week over the third to sixth week period, and five perspectives ((1) pruritus, (2) redness and bleeding, (3) edema, (4) injury and tissue damage, and (5) incrustation and dryness) were independently scored on a scale of 0 to 3. The antibody was administered at 10 mg/kg into the peritoneal cavities the day before sensitization and each induction, 6 times in total (BM095 group), or the day before each induction after the third week, three times in total (V/B group). As a positive control, 1 mg/kg dexamethasone was orally administered every day after the third week (DEX group). Each group contained 10 male NC/Nga mice.

As shown in FIG. 2, a significant suppressive effect was found in the antibody-administered group as compared to the solvent-administered vehicle group. In addition, as seen in FIG. 2, whereas significant weight loss was found in the DEX group, there was no weight change in the antibody-administrated group. This suggests that the antibody is a very safe agent.

Example 5 Assessment of Drug Efficacy Using a Chronic Dermatitis Model Created by Repeated Application of Picryl Chloride

Six-week-old female BALB/c mice were sensitized by applying 20 μl of 0.5% picryl chloride (acetone/olive oil (1:4 v/v) solution) on their right ears. The induction was achieved by repeatedly applying 20 μl of 0.25% picryl chloride (acetone/olive oil (1:4 v/v)) on their right ears every two days since the eighth day after sensitization. 10 mg/kg of BM095 was administered into the peritoneal cavities once a week since the day before sensitization in the group for evaluation of the preventive effect of BM095 or since the 20th day after the start of induction in the group for evaluation of the therapeutic effect of BM095. Auricle swelling was evaluated by sequentially measuring the thickness of right ear using a dial thickness gauge.

As a result, a significant suppressive effect was found in the antibody-administered group, as seen in FIG. 4. The expression of human NR 10 was reported to be enhanced in thickened epidermis of atopic dermatitis patients (Non-patent Document 1). Auricles of the above-described chronic dermatitis model mice were immunohistochemically stained. As with the case of humans, the expression of mouse NR 10 was observed to be enhanced in the thickened epidermis (FIG. 5; BM095 in which the constant region was replaced with that of human IgG was prepared in Example 3 and used in immunohistochemical staining. Portions stained brown are NR 10 expression sites). This finding suggests that NR 10 is similarly involved in inflammatory diseases in both human and mouse.

Example 6 Assessment of Drug Efficacy Using Collagen-Induced Arthritis (Rheumatism) Model

Preparation of model mice and evaluation of drug efficacy were achieved by the procedure described below.

140 μl of collagen gel, which was prepared by combining equal amounts of Complete Adjuvant H37Ra and 0.3% type II collagen derived from bovine joint, was administered intracutaneously to 9-week old female DBA/1JN mice at the tail head (Day 0; sensitization). After three weeks, collagen gel prepared by the same procedure was administered intracutaneously on the back to induce the onset of arthritis (Day 21; induction). According to the body weights two days before sensitization (Day −2), 16 mice were divided into two groups, each including 8 mice, to set a medium-administered group and a BM095-administered group. Using as a medium 20 mmol/l acetate buffer (pH 5.5) (200 mmol/l NaCl) diluted 6 times with PBS, the test substance BM095 was administered intravenously to the 8 mice of the BM095-administered group at the dose of 10 mg/weight kg the day before sensitization (Day −1). Meanwhile, the same volume of the medium per unit body weight was administered to the 8 mice in the medium-administered group as a control on Day −1. Swelling in the four limbs was observed and evaluated by scoring (on a scale of 0 to 4 for each limb: total score 16) since the day before induction (Day 20) at 2- to 3-day intervals.

As a result, the score for swelling in the four limbs was found to decrease after Day 20 in the BM095-administered group, as seen in FIG. 6. This suggests that BM095 has the effect of suppressing the onset of arthritis.

Example 7 Assessment of Drug Efficacy Using Collagenase-Induced Arthritis (Osteoarthritis) Model

Preparation of Model Mice and Evaluation of Drug Efficacy were Achieved by the Procedure described below.

A control medium (20 mmol/l acetate buffer (pH 5.5) diluted 6 times with PBS, 200 mmol/l NaCl (n=5)), 2 mg/kg BM095 (n=5), and 20 mg/kg BM095 (n=6) were administered (5 ml/kg) intravenously into the caudal veins of 8-week-old male C57BL/6J Jcl mice (CLEA Japan Inc.). Then, 6 μl of 1.5% collagenase solution (Type II; Sigma) filtered through 0.45-μm filter (MILLIPORE) was administered into the right knee joint cavities under anesthesia with inhalation of 3% isoflurane (Am J Pathol 1989; 135(6):1001-14).

The widths of right and left knee joints were determined using calipers (Mitsutoyo CO.) immediately before collagenase administration and 3, 7, and 14 days after collagenase administration to calculate the difference between right and left. The difference was defined as a representative value for right knee joint swelling. The area under the curve (AUC) of transition of this difference was determined based on the trapezoidal rule, and defined as an indicator of drug efficacy. Student's t test was conducted for AUC of the medium control group and CNP-administered group using a statistical analysis software (SAS Institute Inc.) (a significant difference is assumed when p<0.05). As a result, AUC of the BM095-administered group was significantly smaller at any dose than that of the medium control group, as seen in FIG. 7. This result demonstrates that BM095 suppresses arthritis in the osteoarthritis model.

Example 8 Preparation of Anti-Human NR 10 Neutralizing Antibody

Mice were immunized with human NR 10 protein (extracellular domain) {described in Example 2}, and hybridomas were prepared by conventional methods. The culture supernatants of the hybridomas were assayed for the neutralizing activity using the human-IL-31-dependent cell line (hNR 10/hOSMR/BaF3 cells) described in Example 1. Multiple clones exhibiting strong NR 10 neutralizing activity were obtained (FIG. 8).

Example 9 Preparation of Human Chimeric Antibody

The amino acid sequence of the heavy chain variable region of NA633, which exhibited the strongest activity among neutralizing antibodies, is shown in SEQ ID NO: 16, and the amino acid sequence of the light chain variable region is shown in SEQ ID NO: 17. In addition, the amino acid sequences of CDR1, CDR2, and CDR3 of the heavy chain variable region of NA633 are shown in SEQ ID NOs: 18, 19, and 20, respectively; and the amino acid sequences of CDR1, CDR2, and CDR3 of the light chain variable region are shown in SEQ ID NOs: 21, 22, and 23, respectively.

Furthermore, a chimeric antibody comprising the above-described mouse variable region and human constant region (IgG1-type H chain; κ-type L chain) was prepared by a conventional method, and the neutralizing activity was determined. As shown in FIG. 9, the chimeric antibody NA633 exhibited strong neutralizing activity at low concentrations.

Example 10 Isolation of Cynomolgus Monkey NR 10

The inventors tried to isolate the cynomolgus monkey NR 10 gene, because the cross-reactivity and neutralizing activity to cynomolgus monkey NR 10 were thought to be important in safety assessment at the preclinical step. Primers were designed based on disclosed Rhesus monkey genomic information and such, and the NR 10 gene was successfully amplified from organs of cynomolgus monkey by PCR. An alignment of amino acid sequences of human NR 10 and the isolated cynomolgus monkey NR 10 is shown in FIG. 10. The amino acid sequence of the cynomolgus monkey NR 10 is shown in SEQ ID NO: 24. A cell line proliferating in a human-IL-31-dependent fashion was established by introducing the cynomolgus monkey NR 10 gene together with the human OSMR gene into Ba/F3 cells, as described in Example 1. The neutralizing activity of the chimeric antibody NA633 described in Example 9 was tested using this cell line. The result demonstrated that the antibody also exhibited strong neutralizing activity in cynomolgus monkey (FIG. 11).

Reference Example 1 Drug Efficacy of BM095 in Dextran Sulfate Sodium (DSS) Induced Colitis

DSS-induced colitis model (J Immunol (2003) 171:5507-5513), which was reported as a pathological model for inflammatory bowel disease (IBD), was prepared to evaluate the effect of BM095, an anti-mouse NR 10 neutralizing antibody. An aqueous solution of 5% (w/v) Dextran Sulfate Sodium Salt (Wako Pure Chemical Industries) was prepared using distilled water filtered and sterilized with 0.22-μm filter (Millipore). Six-week old male Balb/cAnN Crj mice (CHARLES RIVER LABORATORIES JAPAN) were allowed to freely drink the solution from water bottles for 7 days. The body weights were measured, and percent weight changes relative to the weights on the first day of DSS administration were used as an index of drug efficacy.

Using this model, the anti-mouse NR 10 neutralizing antibody BM095 was intravenously administered at a dose of 10 mg/kg the day before DSS administration and the resulting weight loss was evaluated (n=10) to test whether the pathological condition was improved by neutralizing IL-31 signaling. The group (Vehicle group; n=10) in which a vehicle (a mixture of acetate buffer [20 mmol/L sodium acetate and 20 mmol/L sodium chloride] and phosphate-buffered saline [PBS; GIBCO], which were mixed at a volume ratio of 1:5) was administered intravenously the day before DSS administration, was used as a vehicle control group. Furthermore, the course of percent weight change in Balb/cAnN Crj mice of same sex and age (n=1) as those in the DSS-administered group was also investigated to know the time course of percent weight change in normal mice.

The course of weight is shown in FIG. 12. DSS administration reduced the percent weight change in the Vehicle group. The course of percent weight change in the BM095 administered group was similar to that in the Vehicle group. However, four and five days after DSS administration, the percent weight change was significantly reduced in the BM095 group as compared to the Vehicle group. These results showed that the administration of BM095 produced no therapeutic effect on colitis of the model.

It has been reported that the expression of IL-31Ra is enhanced in this model (WO 2004/003140). The experimental results described above demonstrate that antibodies neutralizing the molecule produce no therapeutic effect on colitis of this model.

Reference Example 2 Drug Efficacy of BM095 in Picryl Chloride-Induced Acute Contact Dermatitis Model

To evaluate the effect of the anti-mouse NR 10 neutralizing antibody BM095, a Dermatitis reported as an acute contact dermatitis model (Clin Immunol (2003) 108: 257-262) was developed. This Dermatitis is a result of a delayed hypersensitivity reaction due to sensitization and induction by picryl chloride application. 50 μL of a solution of 7% picryl chloride (nacalai tesque, Inc.; ethanol:acetone=3:1 (v/v)) was applied onto abdominal skin to sensitize 8-week old female Balb/cAnN Crj mice (CHARLES RIVER LABORATORIES JAPAN), and after 5 days, 20 μL of 1% picryl chloride solution (acetone:olive=1:4 (v/v)) was applied onto the skin of right auricles to elicit contact dermatitis (Induction). 20 μL of a vehicle (acetone:olive=1:4 (v/v)) was applied onto the skin of left auricles of the same mice as a control to evaluate the effect of the vehicle on the thickness of auricle (Positive group; n=6). The thicknesses of right and left ears were measured using a Dial Thickness Gauge (OZAKI MFG.) immediately before induction and 24, 48, and 72 hours after induction, and the change in the thickness of auricle relevant to the thickness immediately before induction was used as an index for drug efficacy.

The group (Negative group; n=6) in which an ethanol-acetone mixture (3:1 (v/v)) without picryl chloride was applied onto the abdominal skin at the time of sensitization, and after 5 days, 20 μL of 1% picryl chloride solution was applied onto the skin of right auricle and 20 μL of a vehicle (acetone:olive=1:4 (v/v)) was applied onto the skin of left auricle, was used as a control group to evaluate the establishment of pathological conditions.

The group (BM095 group; n=6), in which acute contact dermatitis was induced by the same method as that used for the above-described Positive group and then BM095 was administered intravenously at 10 mg/kg the days before sensitization and induction, and the group (Vehicle group; n=5) in which at the same timing a vehicle (acetate buffer [20 mmol/L sodium acetate and 20 mmol/L sodium chloride] and phosphate-buffered physiological saline [PBS; GIBCO], which were combined at a volume ratio of 1:5) was administered, was used to evaluate the effect of administration of anti-NR 10 antibodies on the pathological conditions in the model system.

The changes in auricle thickness up to 72 hours after induction are shown in FIG. 13. The auricle was found to be significantly thickened in the Positive group at each time point of 24, 48, and 72 hours after induction as compared to the Negative group, suggesting establishment of pathological conditions. The transition of auricle thickness in the BM095 group was similar to that in the Vehicle group, and thus, no significant suppression was found.

The results described above demonstrate that the administration of BM095 produce no therapeutic effect on acute contact dermatitis observed in this model.

INDUSTRIAL APPLICABILITY

The present invention provides novel agents for preventing or treating inflammatory diseases. The agents for preventing or treating inflammatory diseases provided by the present invention comprise as an active ingredient an NR 10 antagonist, more preferably, an antibody having NR 10-neutralizing activity.

Monoclonal antibody-based anti-cytokine therapy is drawing much attention in recent years. In many actual pathological conditions, however, it has been difficult to produce therapeutic effects by blocking a single cytokine, because compensatory pathways are activated. Further, it was difficult to estimate in what type of diseases therapeutic effects could be obtained by blocking the target cytokine. Under the circumstance described above, the present inventors discovered that anti-NR 10 neutralizing antibodies could significantly suppress symptoms in model mice with atopic dermatitis, chronic dermatitis, rheumatism, osteoarthritis or such.

The present inventors also succeeded in preparing human NR 10 neutralizing antibodies. Agents for preventing or treating inflammatory diseases, which comprise as an active ingredient human NR 10 neutralizing antibodies, are highly useful for clinical application to humans. 

1-11. (canceled)
 12. An antibody having an NR 10 neutralizing activity.
 13. The antibody of claim 12, which is a monoclonal antibody.
 14. The antibody of claim 12, wherein NR 10 is human NR
 10. 15. The antibody of claim 12, which is a recombinant antibody.
 16. The antibody of claim 15, wherein the recombinant antibody is a chimeric antibody, humanized antibody, or human antibody.
 17. A fragment or a modified fragment of an antibody having an NR 10 neutralizing activity.
 18. A method for preventing or treating an inflammatory disease, which comprises the step of administering an NR 10 antagonist to a patient with an inflammatory disease.
 19. (canceled)
 20. The method of claim 18, wherein the NR 10 antagonist is an antibody having an NR 10 neutralizing activity.
 21. The method of claim 20, wherein the antibody is a monoclonal antibody.
 22. The method of claim 20, wherein the antibody is a monoclonal antibody having a human NR 10 neutralizing activity.
 23. The method of claim 20, wherein the antibody is a recombinant antibody.
 24. The method of claim 20, wherein the antibody is a chimeric antibody, humanized antibody, or human antibody.
 25. The method of claim 18, wherein the NR10 antagonist is a fragment or a modified fragment of an antibody having an NR 10 neutralizing activity.
 26. The method of claim 18, wherein the inflammatory disease is atopic dermatitis.
 27. The method of claim 18, wherein the inflammatory disease is chronic dermatitis.
 28. The method of claim 18, wherein the inflammatory disease is rheumatism.
 29. The method of claim 18, wherein the inflammatory disease is osteoarthritis.
 30. The method of claim 18, wherein the inflammatory disease is rheumatoid arthritis. 